Acoustic horn



FIG. 1 is a left side elevational view of a acoustic horn showing my new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a front elevational view thereof; and

FIG. 5 is a bottom plan view thereof. 

The ornamental design for an acoustic horn, as shown. 